Airplane Range on 100 EC

[OJT]

3 hours ago, camacju said:

Have you tried using fewer blades? I found that two blades per prop worked just fine - the blades need to each contribute more thrust, but you will have lower mass and drag to make up for it.

Also you don't need the 1K battery pack - the 1.25m aerodynamic nose cone works just fine to occlude and you save mass by using that plus a Z-100 battery

As I mentioned earlier in this thread, I tested out various fan blade configurations, from 2 biggest fan blades to 16 smallest ones. I personally found the 8 small fan blades to give me the best balance in terms of speed generated and EC used to get to that speed

And my craft DOES have a nose cone. I placed it in the rear of the fairing to fully occlude that node and then offset it inside the fairing. 1K battery in the meanwhile is placed up front to fully occlude the front node of the fairing. With this, I get a fully occluded fairing base and everything else generating zero drag. Which in turn gives me very streamlined fuselage (by base KSP standards at least). As for the engine, it is placed on the front node of the battery and turned around facing backwards (I included the screenshots of the setup and drag parameters below)

And the mass savings don't really give much advantage, at least in my personal experience. 1K battery back is only 40 kilos heavier than the Z-100 battery, but the drag benefits far outweigh (pun not intended) the lesser mass. This is also the reason why I stuck with the wing configuration that I had: it might be heavier, but with it the plane maintains stable level flight with pretty much no corrections applied by the control surfaces. Other variations I tested out were either too twitchy with control surfaces (therefore losing prograde speed) or just outright unstable. And seeing how well the 2000km entry worked, I decided to go with the "If it ain't broke don't fix it" principle and left wings as they were. With that being said, there are small gains that can be still achieved with careful adjustment of wing and fuselage AoA, but I didn't go as far as to test that out, because simply offsetting the fan blades inwards already more than doubled the range from my previous entry

Edited May 31, 2022 by OJT

[camacju]

9 hours ago, OJT said:

1K battery in the meanwhile is placed up front to fully occlude the front node of the fairing

Yeah I know how root fairing works. I was suggesting something as follows:

-Place nose cones on the front and back nodes of the fairing (both nodes will be almost fully occluded - if you look at the WDrg values in your fairing, you'll see 0.49 WDrg value for your rear node, which is not optimal. Note that your fairing has 0.14 OccA for both nodes instead of zero)

-Place the engine on an interstage node of the fairing to occlude more area (Interstage nodes count for node occlusion)

-Place octagonal struts on interstage nodes to occlude the rest of the area

As is, you're not fully occluding the frontal and rear area of the fairing, while also eating the mass penalty from using the 1K battery bank (It's 40 kg, while the nose cone is only 30 kg).

For future reference, the octagonal strut is the single best part in terms of occlusion area per mass (at least for 0.625m and 1.25m parts), but you can't fit enough on the interstage nodes to fully occlude a fairing, so the aerodynamic nose cone is necessary (as it's the best 1.25m part for occlusion area per mass).

Edited May 31, 2022 by camacju

[OJT]

3 hours ago, camacju said:

Yeah I know how root fairing works. I was suggesting something as follows:

-Place nose cones on the front and back nodes of the fairing (both nodes will be almost fully occluded - if you look at the WDrg values in your fairing, you'll see 0.49 WDrg value for your rear node, which is not optimal. Note that your fairing has 0.14 OccA for both nodes instead of zero)

-Place the engine on an interstage node of the fairing to occlude more area (Interstage nodes count for node occlusion)

-Place octagonal struts on interstage nodes to occlude the rest of the area

As is, you're not fully occluding the frontal and rear area of the fairing, while also eating the mass penalty from using the 1K battery bank (It's 40 kg, while the nose cone is only 30 kg).

For future reference, the octagonal strut is the single best part in terms of occlusion area per mass (at least for 0.625m and 1.25m parts), but you can't fit enough on the interstage nodes to fully occlude a fairing, so the aerodynamic nose cone is necessary (as it's the best 1.25m part for occlusion area per mass).

Huh, fairing aerodynamics are even weirder than I thought 

I will try your suggestions when I get free time, currently busy with exams

[18Watt]

On 5/31/2022 at 1:47 PM, OJT said:

I will try your suggestions when I get free time, currently busy with exams

I've updated the leaderboard, please advise if I left somebody off- I've been crazy busy at work lately, often no internet for long stretches.

One of my original goals with this challenge was for it to be a reasonably quick challenge, something that doesn't require 6 hours to complete.  I'm not sure there is even a true limit to what can be achieved with 'stock' (need the BG expansion pack..) KSP propellers.  I'm 100% convinced that I've learned more about KSP aerodynamics than the contestants have from this challenge.  Aside from tweaking propellers, optimizing KSP aero properties has become clearer to me when using such low part count vessels.

Again, I've been out of internet for a week or so now, so let me know if I've left a valid entry off the leaderboard

[swjr-swis]

1 hour ago, 18Watt said:

I've updated the leaderboard, please advise if I left somebody off

Not even an honorary mention for the infinite range plane? You're actually gonna make me sit through 3-4 circumnavigations to secure that top spot? Sad face.

[imcute]

can i use other ways to generate electricity without using modded parts modified parts power-generating engines or power parts?

eg:underclocked power-consuming engines

[18Watt]

15 hours ago, imcute said:

can i use other ways to generate electricity without using modded parts modified parts power-generating engines or power parts?

No, that is against the rules.

[imcute]

aww man